Category Archives: Uncategorized

Selective modulator of cannabinoid receptor type 2 reduces memory impairment and infarct size during cerebral hypoperfusion and vascular dementia.

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“Vascular dementia is the highly devastating neurodegenerative disorder after Alzheimer’s disease (AD) and mainly found in aged people but the effectual therapeutic target is still not there.

Chronic cerebral hypoperfusion (CCH) has been broadly found in vascular dementia (VaD) patients. CCH is thought to link with neurodegenerative disorders and their subsequent cognitive deteriorate on.

This study has been framed to examine the role of a selective agonist of cannabinoid receptor type 2(CB2); 1-phenylisatin in CCH induced VaD.

These results indicate that 2VO induced CCH in rats, which was attenuated with the treatment of 1-phenylisatin.

Hence, it may be suggested that modulation of cannabinoid receptor may provide benefits in CCH as cognitive impairment and VaD.

Therefore, selective agonists of CB2 receptors may be a potential research target for the alleviation of VaD.”

http://www.ncbi.nlm.nih.gov/pubmed/27586843

Peltatoside Isolated from Annona crassiflora Induces Peripheral Antinociception by Activation of the Cannabinoid System.

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“Peltatoside is a natural compound isolated from leaves of Annona crassiflora Mart., a plant widely used in folk medicine.

This substance is an analogue of quercetin, a flavonoid extensively studied because of its diverse biological activities, including analgesic effects. Besides, a previous study suggested, by computer structure analyses, a possible quercetin-CB1 cannabinoid receptor interaction.

Thus, the aim of this work was to assess the antinociceptive effect of peltatoside and analyze the cannabinoid system involvement in this action.

Our results suggest that this natural substance is capable of inducing analgesia through the activation of peripheral CB1 receptors, involving endocannabinoids in this process.”

http://www.ncbi.nlm.nih.gov/pubmed/27574895

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Endocannabinoid mechanism for orofacial antinociception induced by electroacupuncture in acupoint St36 in rats.

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“This study was conducted with the aim of evaluating whether electroacupuncture (EA) at acupoint St36 could produce antinociception through the activation of an endocannabinoid mechanism.

CONCLUSION:

This study demonstrated for the first time that the CB1 cannabinoid receptor participates in the antinociceptive effect induced by EA.”

http://www.ncbi.nlm.nih.gov/pubmed/27573715

Characterization of non-olfactory GPCRs in human sperm with a focus on GPR18.

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“G protein-coupled receptors (GPCRs) transduce external chemical cues into intracellular signals and are involved in a plethora of physiological processes, but knowledge regarding the function of these receptors in spermatozoa is limited. In the present study, we performed RNA-Seq and analyzed the expression of the all GPCRs except olfactory receptors in human spermatozoa. We revealed the expression of up to 223 different GPCR transcripts in human spermatozoa (FPKM > 0.1) and identified GPR18, a newly described cannabinoid receptor, together with GPR137 and GPR135, as one of the three most highly expressed GPCRs. To date, the expression of GPR18 was completely unknown in human spermatozoa. We confirmed GPR18 expression using RT-PCR and immuncytochemistry experiments and localized the GPR18 protein in the midpiece of human spermatozoa. Stimulation of human spermatozoa with the GPR18 ligand N-arachidonoylglycine induced the phosphorylation of 12 protein kinases, some of them are for example known to be involved in the acrosome reaction. In line with this, N-arachidonoylglycine affected the cytoskeleton by changing levels of F-actin and inducing the acrosome reaction in human spermatozoa in a concentration-dependent manner. Our results indicate that GPR18 might be involved in physiological processes of human spermatozoa, suggesting GPR18 to be a potential player in sperm physiology.”

http://www.ncbi.nlm.nih.gov/pubmed/27572937

“Cannabinoid receptor activates spermatozoa”               http://medicalxpress.com/news/2016-08-cannabinoid-receptor-spermatozoa.html

Cannabinoid 2 receptor is a novel anti-inflammatory target in experimental proliferative vitreoretinopathy.

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“Proliferative vitreoretinopathy (PVR) can develop after ocular trauma or inflammation and is a common complication of surgery to correct retinal detachment.

Currently, there are no pharmacological treatments for PVR.

Cannabinoids acting at cannabinoid 2 receptor (CB2R) can decrease inflammation and fibrosis.

The objective of this study was to examine the anti-inflammatory actions of CB2R as a candidate novel therapeutic target in experimental PVR.

In conclusion, our results indicate that intervention at early stage PVR with CB2R agonists reduces ocular inflammation and disease severity.

CB2R may represent a therapeutic target to prevent PVR progression and vision loss.”

http://www.ncbi.nlm.nih.gov/pubmed/27569993

Activation of type 1 cannabinoid receptor (CB1R) promotes neurogenesis in murine subventricular zone cell cultures.

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“The endocannabinoid system has been implicated in the modulation of adult neurogenesis.

Here, we describe the effect of type 1 cannabinoid receptor (CB1R) activation on self-renewal, proliferation and neuronal differentiation in mouse neonatal subventricular zone (SVZ) stem/progenitor cell cultures.

There is an emerging consensus that endocannabinoid signaling plays a major role in adult neurogenesis.

Cannabinoids act on at least two types of receptors, the type 1 and type 2 cannabinoid receptors (CB1R and CB2R), which are, respectively, predominantly distributed in the central nervous system (CNS) and immune system, although some studies have described the presence of low levels of CB2R in the brain.

Taken together, these results demonstrate that CB1R activation induces proliferation, self-renewal and neuronal differentiation from mouse neonatal SVZ cell cultures.

 Collectively, CB1R agonists render neurons less excitable and thus promote neuroprotection.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3660454/

Targeting the endocannabinoid system: future therapeutic strategies.

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“The endocannabinoid system (ECS) is involved in many physiological regulation pathways in the human body, which makes this system the target of many drugs and therapies. In this review, we highlight the latest studies regarding the role of the ECS and the drugs that target it, with a particular focus on the basis for the discovery of new cannabinoid-based drugs. In addition, we propose some key steps, such as the creation of a cannabinoid-receptor interaction matrix (CRIM) and the use of metabolomics, towards the development of improved and more specific drugs for each relevant disease.”

http://www.ncbi.nlm.nih.gov/pubmed/27554802

Orchestrated activation of mGluR5 and CB1 promotes neuroprotection.

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“The metabotropic glutamate receptor 5 (mGluR5) and the cannabinoid receptor 1 (CB1) exhibit a functional interaction, as CB1 regulates pre-synaptic glutamate release and mGluR5 activation increases endocannabinoid synthesis at the post-synaptic site. Since both mGluR5 and CB1promote neuroprotection, we delineated experiments to investigate a possible link between CB1 and mGluR5 activation in the induction of neuroprotection using primary cultured corticostriatal neurons. We find that either the pharmacological blockade or the genetic ablation of either mGluR5 or CB1 can abrogate both CB1– and mGluR5-mediated neuroprotection against glutamate insult. Interestingly, decreased glutamate release and diminished intracellular Ca2+ do not appear to play a role in CB1 and mGluR5-mediated neuroprotection. Rather, these two receptors work cooperatively to trigger the activation of cell signaling pathways to promote neuronal survival, which involves MEK/ERK1/2 and PI3K/AKT activation. Interestingly, although mGluR5 activation protects postsynaptic terminals and CB1 the presynaptic site, intact signaling of both receptors is required to effectively promote neuronal survival. In conclusion, mGluR5 and CB1 act in concert to activate neuroprotective cell signaling pathways and promote neuronal survival.”

 http://www.ncbi.nlm.nih.gov/pubmed/27543109

Peripheral and central CB1 cannabinoid receptors control stress-induced impairment of memory consolidation.

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“Stressful events can generate emotional memories linked to the traumatic incident, but they also can impair the formation of nonemotional memories. Although the impact of stress on emotional memories is well studied, much less is known about the influence of the emotional state on the formation of nonemotional memories.

We used the novel object-recognition task as a model of nonemotional memory in mice to investigate the underlying mechanism of the deleterious effect of stress on memory consolidation.

Systemic, hippocampal, and peripheral blockade of cannabinoid type-1 (CB1) receptors abolished the stress-induced memory impairment. Genetic deletion and rescue of CB1 receptors in specific cell types revealed that the CB1 receptor population specifically in dopamine β-hydroxylase (DBH)-expressing cells is both necessary and sufficient for stress-induced impairment of memory consolidation, but CB1 receptors present in other neuronal populations are not involved.

Strikingly, pharmacological manipulations in mice expressing CB1 receptors exclusively in DBH+ cells revealed that both hippocampal and peripheral receptors mediate the impact of stress on memory consolidation.

Thus, CB1 receptors on adrenergic and noradrenergic cells provide previously unrecognized cross-talk between central and peripheral mechanisms in the stress-dependent regulation of nonemotional memory consolidation, suggesting new potential avenues for the treatment of cognitive aspects on stress-related disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/27528659

Metabolism of endocannabinoids.

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“Endocannabinoids belong to a group of ester, ether and amide derivatives of fatty acids, which are endogenous ligands of receptors CB1, CB2, TRPV1 and GPR55 that are included in the endocannabinoid system of the animal organism. The best known endocannabinoids are: N-arachidonylethanolamide called anandamide (AEA) and 2-arachidonoylglycerol (2-AG). They occur in all organisms, and their highest level is observed in the brain. In this review the mechanisms of synthesis and degradation of both AEA and 2-AG are shown. Endocannabinoids are synthesized from phospholipids (mainly phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol) located in the cell membrane. As a result of arachidonic acid transfer from phosphatidylcholine to phosphatidylethanolamine, N-arachidonoyl phosphatidylethanolamine is formed, which is hydrolyzed to AEA by phospholipase D, C and A2. However, 2-AG is formed during the hydrolysis of phosphatidylinositol catalyzed mainly by DAGL. The primary role of endocannabinoids is the activation of cannabinoid receptors. Both AEA and 2-AG are primarily agonists of the CB1 receptor and to a lower degree CB2 and TRPV1r eceptors, but 2-AG has stronger affinity for these receptors. Through activation of receptors, endocannabinoids affect cellular metabolism and participate in the metabolic processes by receptor-independent pathways. Endocannabinoids which are not bound to the receptors are degraded. The main enzymes responsible for the hydrolysis of AEA and 2-AG are FAAH and MAGL, respectively. Apart from hydrolytic degradation, endocannabinoids may also be oxidized by cyclooxygenase-2, lipoxygenases, and cytochrome P450. It has been shown that the metabolites of both endocannabinoids also have biological significance.”

http://www.ncbi.nlm.nih.gov/pubmed/27516570